Ray Arritt, Dave Flory, Bill Gutowski, and Gene Takle

NARCCAP: Status Report and Some Preliminary Results

North America Regional Climate Change Assessment Program: Participants

• Raymond Arritt, David Flory, William Gutowski, Gene Takle, Iowa State University, USA

• Richard Jones, W. Moufouma-Okia, Hadley Centre, UK• Daniel Caya, Sébastien Biner, OURANOS, Canada• Phil Duffy, Lawrence Livermore National Laboratories, USA• Filippo Giorgi, Abdus Salam ICTP, Italy• Isaac Held, NOAA Geophysical Fluid Dynamics Laboratory, USA• René Laprise, Univ. de Québec à Montréal, Canada• Ruby Leung, Y. Qian, Pacific Northwest National Laboratories, USA• Linda Mearns, Don Middleton, Doug Nychka, Phil Rasch, Tom Wigley,

National Center for Atmospheric Research, USA• Ana Nunes, John Roads, Scripps Institution of Oceanography, USA• Steve Sain, Univ. of Colorado at Denver, USA• Lisa Sloan, Mark Snyder, Univ. of California at Santa Cruz, USA

Current statusWorking data sets:

• UC - Santa Cruz (RCM3 designation)

– Longitude variable differs other models with negative longitudes for western hemisphere.  Precip and 500 mb heights through 1991.

• PNL (mm5p and wrfp designation)

– Two files incomplete when transferred (Ruby has been contacted). Precip and 500 mb heights through 1985. Error in interpolation for 500 mb height from WRF.

• OURANOS (MRCC designation)

– All files checked via checksums and are working fine.  Precip and 500 mb height through full period.

Current status

Not Working data sets:

• Hadley Centre (PRECIS) – Files provided as monthly mean values.  Not usable as

submitted but able to processes after using ncdump | ncgen. Monthly output rather than 3-hour.

• Scripps (ECPC) – Individual netCDF files provided for every output time step. 

No internal timestamp. Variable and dimension names, etc. differ from specs. Output through 1987. (All this is straightforward to fix, except timestamp.)

NARCCAP Plans

• Phase I: 1979-2004 driven by Reanalysis 2– establish uncertainty in RCMs

• Phase IIa: RCMs driven by AOGCM 20th century climate (nominally 1971-2000)

• Phase IIb: RCMs driven by AOGCM SRES A2 scenario 2041-2070

GFDL CGCM3 HADCM3 CCSM MM5 X X RegCM3 X X MRCC X X PRECIS X X X X RSM X X WRF X X X

The Matrix

Any changes?

Some data issues

• Time coordinate: Days versus hours.

– Recommendation: Hours would be simple integer; days may be easier for end users.

• Bounds for coordinate variables (space and time)

– Recommendation: Drop bounds for spatial coordinates. Keep bounds for time.

• Include projection information in metadata (following ENSEMBLES)?

– Recommendation: Yes. See example sent by Hadley Centre.

Some data issues

• Reporting domain: Send the entire domain to the archive or only the region inside the forcing frame (aka sponge zone)? 

– There does not appear to be any straightforward way of subsetting for users.

– Recommendation: Exclude forcing frame

• Output transmittal to archive: ftp vs. mailing external hard drives (“FedEX Net”)? 

– Recommendation: External hard drives. (Hadley Centre may prefer DLT cartridges.)

Meetings

• "Downscaling to local and regional scales" (IAMAS session MS016) at the IUGG Conference in Perugia, Italy 2-13 July 2007.

• Designate a regular professional conference for NARCCAP meetings? Would help to save travel time and funds.

– Recommendation: Fall AGU (consistent location; easy to reach). Propose a regional modeling session at each meeting; maybe a NARCCAP session at later stages.

Some preliminarypreliminary results

• Results are shown here for 1979-1985 from three RCMs.

• Observed precip is from the CRU 0.5o data set.– probably underestimates precip in high terrain –

need to look at other precip data sets

Analysis Regions

Northern Plains: flat terrain, early summer precip maximumPacific Northwest:

mountainous terrain, winter precip maximum

Precipitation, 1979-1985

Mean annual cycle of precipitation

Mean annual cycle - Northern Great Plains

0

1

2

3

4

5

6

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

MRCCPNLMM5REGCM3Observed (CRU)

January 1980 – ENSO neutral

January 1981 monthly mean 500 mb height

reanalysis

July 1982 monthly mean 500 mb height

reanalysis reanalysis

500 mb heights

January 1983 – strong El Niño

NARCCAP Project Timeline

1/06 12/07 12/0812/06

Start Current Climate GCM1

6/06

End reanalysis

9/06

AOGCM Boundaries available

End Future climate GCM1

6/07

End Current GCM1

End Current

and Future GCM2

Project Start

Finish obs SST Finish delta SST

Time slices

RCMs

?

current date

current status